You probably have a shorted wire going to the motor or switch. You'll have trace the wires and find the damaged section.
Remove the wiring harness from the back of your 2005 Chevy Cavalier heater blower motor. Remove the heater blower motor retaining bolts. Remove the heater blower fan.
Motor hasseized.
Blown fuse, defective blower motor, or defective blower motor resistor pack.
Blown fuse, defective Blower Motor Resistor Pack, Defective Blower Motor, or Defective Blower Motor speed control switch.
There might be a bad fuse causing the heater to not work. Check the fuses if they are all ok you may have a bad blower motor. when you turn the heater on and no air is blowing then it is your blower motor.
If the heater is blowing the fuse when the blower is turned on, I would suspect the blower motor is defective or locked up. If the A/C is blowing a fuse, suspect a bad clutch, or locked up compressor.
Heater blower motor is defective and locked up, or possible short in the wiring.
check for a blown fuse that says heater or blower motor
try replaceing the switch that controls the low to high for heater It's gonna be the blower motor resistor (near the blower motor).
Bad blower motor fuse? Bad blower motor resistor pack? Bad blower motor - checck to see if it is getting power--if so bad motor Bad switch?
Check the fuses.If not the fuse, test the resistor down by the blower motor.
Ok..I figured it out. Turns out the rear defroster is the problem. When I unplugged it from the back windshield, blower/heater works great!! So...to all those out there..if your blower motor blows fuses...check the blower motor first...then the HVAC and heater fuses, then rear defroster if you have a cavalier!